Tensioning devices are used for anti-skid chains in order to avoid an undesired return of the tension cable against the direction of tension after assembly. A possible application of the turnbuckle on the anti-skid chain, or rather the tension cable, is known e.g. from AT 412 202 B.
A tensioning device of the type named in the introduction is envisaged in DE 297 03 911 U1. In this tensioning device, a housing is provided, in which the tension cable can be wound up on a winding drum that is joined torque-proof to a ratchet wheel. The winding drum is pre-stressed for winding up the tension cable in the winding-up direction by a spring. The winding up of the tension cable can be activated by an operating lever which is affixed on the exterior of the housing. A disadvantage of this device is the relatively impractical manipulation of the operating lever, which can also easily get jammed if it gets dirty or icy.
Turnbuckles are known from AT 504 476 B and AT 504 599 B for which a mass piece is provided that is moved radially outwards when mounted by the emerging centrifugal force in the turnbuckle upon the rotation of a wheel. A wire-shaped, free end section of a tension cable is clamped by the movement of the mass piece. In the turnbuckle underlying the present invention, however, there is no free end provided to the tension cable on which a clamping element could act. Rather, the tension cable and hence its end section is wound up on a winding roll of the turnbuckle. Inherently to their design, the known embodiments are not well suited to temporary fixing of a tension cable of a turnbuckle of the type named in the introduction, since, in a generic turnbuckle, direct catching of the tension cable by a moving mass piece would lead to a complicated construction of the turnbuckle.
In U.S. Pat. No. 2,593,018 a chain joint is disclosed in which an end of a chain cable ends in a ring link that is pulled into the chain joint by spring force. The ring link furthermore has a shoulder that rests on an edge of the chain joint housing while the ring link is retracted, and is held there provided that the chain joint is located in a suitable position of orientation. A release pin is provided for release of the ring link.